I have made a comparison between 18.104.22.168 and 22.214.171.124 in file systems and databases. There is only one notable change in sendmail.php file. All the other files have minor changes in one line, 2016 year is now 2017 and 33 file names have been changed to 126.96.36.199.
A question is rising up, what is really 188.8.131.52 release? It is promoted with a lot of security patches but is not different than 184.108.40.206 except one file sendmail.php. I expected improvements or bug fixes but nothing was found so far. Very disappointed how Magento team is managing the new versions.